Fuse



Oct. 5, 1943. T. B. DOE ETAI.

2 Sheets-Sheet 1 FUSE Filed Aug. 8, 1940 INV EN TOR S RobebLKeamgo A TTORNE Y Oct.v 5, 1943.

T. B. DOE ET AL FUSE Filed Aug. 8, 1940 2 Sheets-Sheet 2 H| i Il Patented Oct. 5, 1943 -v it New `tion oijNew York.

City, Nl, if. a corpora:

'v Apers-ation August. 8, 194e, seriaineaiss f circa-Jbl 'l l 1 A imanes." This. invention relates to lses for projectilesn and more particularly to ruses for detonating' a proectile'ata. desired point in. its ight.

`Ari object of the. invention is to. provide a fuse for `a projectile which functions uponnthe projectile being retarded to: a. velocity` corresponding to the desi-'redpoint 'initsfV night to detonate the projectile. r

assembly, shipment and storage. v

Another object of the invention is'. tcproviae' a fuse for a projectile in which a. predetermined difference between the air pressure on the nose of the fuse and a selected air pressure set inA a sealed chamber Within the fuse.' causes the fuse to function.v s

Another objectr of the invention is toi provide a fusefor a projectile! in' which` the iiring-.pirr` or hammer, which held an inoperative con@4 dition until the projectile has reached a 'predetermined pointY its flight;y is released when the set air pressure predominates' by af predetermined value.

Another object of the inventionis to provide a fuse for a projectile in which a. plurality of diaphragms. form Vsurfer-.es on which `the action of air from a chamberin'the fuse set/at a predetermined pressure and ofair'trom an opening at the nose of theV fuse under a pressure due to the velocity of thev projectile in its. flight cause the fuse to function at. a. predeterminedpoint in its flight, i

Fig. 1 is a vertical cross-semmai viewer an embodiment of the invention taken online i'lv offFig.`2; l Y

Fig. 2 is a horizontalv cross-Sectional View taken on line 2.-.2 of Fig. v11'; s

Fig. 3' is a horizontal'fcrossesectional view taken on line 3-3 of Fig. 1;

Fig.v 4 is, similar tof'Fig. .1,' but showing'the relation of parts Within the Vfuseafter the pror time the projectile is red and'burnsto the detonating charge of the projectileV in an interval of time depending on'the point of ignition.` of the powder train, These fuses notonly 'require that there be placed in the fuse itself a considerable amount of powder, which mustfbe manufactured with care that the `rate of 'propagation of the flame be known and constant; but their con-.-

struction'. haslieensnch-r that they` also. require that thepowder trainbe assembled with the fuse atthe factory; with the attending dangers during To overcome; these Adisadivani:ages;

or detonating capsltherein., The loading of the fuse, with; powderfand the insertion of 'thefirin'g caps are' .s uch simple operationsthat they may` be doney iustbeforesecuringthe., fuse on the projectile.

y The vfuse of the present, invention is-iredzbya.y ring pin or-'ring hammer: whicnis moved centrifugal force acting upon'the-hammermass,

the hammer being'held in a fixed position by a.

datent until therdesired time. of'detonatiomy This detent .is pulled out ?o-r..en'gagement With'the hammer when the projectile has reached determined point in its Hight.

It iswellknown that the air pressure Von the nose of a fuse. off a projectile,- varies with the..

Velocity oiV the projectile and the yconditions' of thefatmosphere; through which it passes and that the velocity of the projectile varieswiththe time of ight vand thev angle of-elevation untilrv the` projectilehas reached its maximum height in the tables. i

lTo release thedetentthere `is''fprovidedl an" opening in the nose of the fuse which is in corn-r munication with one sideV of. each of two diaphragms, the'other sides of which are in communicationfwith'an V-air chamber inthe fuse in which has been sealedairat a "pressurecorre-f spending tothe point of detonation desired; .The

detent is connected" to one ofthe, diaphagms and releases the firing hammer When Ghanese airpressiire has` been reduced to anamountsuch that this'diaphragm is more@ under the pressure of the air in the, sealed.;c*hamber,r 'lherequiredpressurein thesealed chamber is. determinecl'by the range. at. which it is dcsiredfthat the projecs tile loe-detonated and thediierence in pressure'v i onthetwo sides of the diaphragm that is neces-,gy

sary to snap it over from one'postion'tolanotherr ,i

.It will therefore be seen thatwhenthe pro'jeca tilehasreached, the desired range,V the diaphragm will be snapped over and the ring hammer will' s be released from its-restrained positionm:'Ilhe`V s t hammer willjthen move outward againstone of the firing-caps under the .action eci; centrif-unal;v

thepresent. invention provides a fusexivhioh` may be .mariu-` factured; shippedv and stored without any-powder af pre;-

which causes unreliability in their movement. It. will be apparent at once that the present invention has overcome the disadvantages inherent in :.j,

these previously disclosed arrangeiments.fv

Referring to the drawingsY and particularly Fig. 1, I represents the conical walls of the fuse The secured to the core 2 by screw threads 3. lower part of core 2, base 4r, is adaptedto be screwed into the nose of the lprojectile. A

hollow cylindrical-shaped member 5, is `adaptedto be secured by screw threads to the nose of the fuse such that the bore 6 of member 5 is aligned with an opening I in the nose of the'fuse.

In the base l is formed a cylindrical cavityt v at each end of which are ringcaps 9 held against passages it in screw plugs I2 which abut against the shoulders II` at the ends of cavity 8. The'passages IFJare `filled with ignition powder IS which is in contact withiiring caps 9, Ignition powder' also lls the passages I4 and ISIlead-l ing to the lower face of the base d. y"Passage I is in communication with the detonating charge in the projectile (not shown). Firing caps', screw plugs I2 and ignition powder I3 may be placed in position just before the fuse is secured on the projectile.`

In cavity 8 is a double ended ring pin or ring hammer IG which is acted upon-by centrifugal force when the shell isfin flight, due to its rotation about 'its longitudinal axis. l Hammer Iii is held in its central position by detent I'I engaging shoulders I8 of the hammer IB. Detent I 'l slides in and out of engagement with hammer Iii with the movement of diaphragm I9 to which it is attached by a riveted or soldered head 2@ on a shoulderedlug 2l. It is preferable toassemble lug 2| to diaphragm I9 with a slight clearance between lug 2| Vand detent Ilrto allow the diaphragm I8 to move slightly under pressure Y,

before it is required to overcome the static resistance of detent i1 incore 2. It has been found that with. this clearance the differential pressure required to snap over the diaphragm is more uniform. N y Diaphragm-i9 isV secured to an outwardly extending flange portion 22 of member 5.- The upwardly extending portion of diaphragm I9 and the outer vertical sides of ilange 22 form with the walls I a passage 23 connectingchamber 2, formed by the walls land the outer surface oi the member 5, with the space 25 surrounding the diaphragm I9. Space 25 is also in communication with cavity 8 by passages 26. Cavity 8 is placed in communication with chambers 24 and 25 to avoid the necessity ofmmaking the'detent I'Iair-tight as to 4cavity 8.

On the under side of iiange 22 and above the diaphragm I9 is a second diaphragm 2. The space 28 between the diaphragm 21 and the lower face of flange 22 is 'incommunication with cham-l ber 24 by passageway 29. The space 30, between diaphragme I9 and 2l, is in communication with bore S by passage 3! and reduced bore 3?. in member 5. y v Y Inthe wall of membery 5 is`a port SSgiving communication between chamber 24 and bore 6 and diametrically opposite port 33 and above it is secured a pin 34 which extends into bore Within bore E slides a hollow split cylinder 35, whose outside diameter is very slightly greater than the diameter of bore 6 so that the cylinder may t tightly within bore 6. Pin 34 engages the slot 36 in split cylinder 35` and acts as a guide to assure that` the slot .36 is always out of alignment with the port 33,

Operation v lhen it is desired to set the fuse to detonate the projectile at apredetermined point in its night, the air pressure on the nose of the projectileisfound` from range-nose pressure curves vand chamber 24l is charged with this pressure,

plus the differential pressure required on the two faces of diaphragm I9 to snap it over from one .position to another. This differential pressure lias'been found to be approximately ten pounds. If, iforlexample, it .is desired `to detonate the projectile when it has reached a point in its iiight corresponding to seventy-five pounds per square `inch of nose pressure, chamber `24v and space 25 are charged to a .pressure of` eighty-five pounds per square inch through opening .'I andbore 6. This pressure is also exerted in space 28 through passage 29 and temporarily to space 3E) through bore ,32 and passage 3| Diaphragme I9 and 2'! are kept a minimum distance` apart by `protuberancesv 3'! extending from `the lower side of diaphragm 21.

When the chamber 24 and associated spaces are charged tothe desired pressure, split cylinder 35fis shoved down tothe bottom of bore 6, as shown in Fig. 4,v thus sealing `chamber 24 and associated spaces. The outside source of lcompressed air is then disconnected and space `Sil is reduced to atmospheric pressure through passageway 3|, bores 32 and and opening l.

The diaphragms I9 and 2'I remain in the position shown in Fig. 1 4as the'set pressure in the fuse actinggon theoutside of diaphragm I9 and the inside of diaphragm -2'I are balanced through the protuberances 31 which are in contact with the inner side of diaphragm I9,

- It will be noted that; diaphragm 21, both before and after charging the fuse to theset pressure, .acts vas a safety element to support the diaphragm i9 in its normal position. i The diaphragm 2 is preferably `made stiffer than diaphragm `I3 and thereby make's'a strong mechanical support for'the diaphragm I9 before the fuse is charged. 'A -convenientway to make diaphragm 2'! `stiffer thanfdiaphragm I9 vis to make its radius of curvature lsmallerthan that of diaphragm I9. i

Whenv the projectileis "iired, the nose air pressure increases' to about one hundred and iteen pounds per square inch for an initial velocity of the projectile of 2400 4feet per second. This pressure is communicated to space'Bl) through openi ing '1, bores 6 and 32 and passageway 3|, and as this pressure is greater than the pressure exerted on the upper side of `diaphragm 2l, diaphragm 27- is-snapped over to the position shown in Fig. 4,

`thusremoving the protuberances' 31 from conthe position shown in Fig. 5.k Deterit I1, con-A nected to diaphragm I9, `is thereby drawn out of engagement with hammer I6 which is'free to be moved by centrifugal force to one end or the other of cavity 8 where it sets oi one of the firing caps 9, igniting powder train I3', .whichV detonates the powder in the projectile.

While the preferredembodiment of the invention has been described it is evident thatrvarious modifications are possible without depart-V ing from the scope of the invention as expressed in the claims.

We claim:

1. In a fuse for projectiles, the combination of a core and a firing cap therein, a'ring hammer movable in the core and adapted to strikel the firing cap, a movable member having two f having two opposed sides, one of said sides being o positioned adjacent to the second side of the rst movable member, an air chamber formed in part by the adjacent sides of the twoV movable l members, a second air chamber vformedin part by the outer sides of the two movable members, a passage connecting the first mentioned air controlling said port.

2. In a fuse for projectiles, the combination of a core and a firing cap therein, a firing haml mer movable in the core and adapted to' strike the firing cap, a snap diaphragm secured, at its periphery to the core and normally dished tov ward the ring hammer, a detent attached to the diaphragm andl normally adaptedto hold the hammer in a fixed position, a second snap diaphragm secured at'its peripheryto the core adjacent to the second side of the` first diaphragm, said second diaphragm beingnormally dished in the same directionas the first ,dia-V phragm, an air chamber formed in part between the adjacent sides of the two diaphragms,-

a second air chamber formed in part` by the an opening -in the nose of the fuse, an 'externally accessible portcommunicating with the vsecond j`v v e, air chamber, and valvey means controlling said j ,Y v port. i

3, In a fuse phragm, an air chamber formed in partabef tween the adjacent sides of the two diaphragins, j .L a second air chamber formed in part by the outer. sides of the' two'diaphragmvs, a passage connecting the rst mentioned air chamber to an open'-l j ing in the nose of the fuse, a'port connecting the. f

valve second airv chamber to the passage, and means for controlling lthe port. g

4. In Ya fuse for projectiles, the`'combin'ation''ofr acore and a firing cap therein, a ring hammer movable in the ycore and adapted,y to strike the firing cap, a snapdiaphragin secured at" itsi periphery to the core and normallydished tof vward the ring hammer, a detent attached tov the diaphragm and normally adapted rtohold ythe 'hammer in a fixed position,` a second snap` k diaphragm secured at its periphery to thea core Y 'adjacent toVv the second side of ythe `iirst diai phragm, saidV second diaphragm being normally dished 'in'tl'ie l same direction as the first diav phragm, -means attached to Vone ofthe ydiaif i phragms for keeping said. diaphragme separated a minimum distance 1 from each other,an air, chamber formed inzpart between the adjacent sides of the two' diaphragms, a second airchainber formedv in part bythe outer sides of thetwo D diaphragms, a passage connecting the irstnienf; A. Y, tioned air" chamber to-an opening i n. thefnose` j of the fuse, an exterisially` 'accessible port :com- Ty municating with ythe second air chamber, and* 4 Valvenieansy controlling said port.

- 'IHQMASB.DoE-. 1

RoBEaTx l1.. KENNG outer sideslof the two diaphragms, a passage-r Y connecting the first mentioned air chamber'to vfor projectiles, the combination;

yof, a core and a firing cap therein, a firing hammerr movable .in the core and adapted to' strike.;v` the rng cap,.a snap ldiaphragm secured at its o periphery to the core and normally dishedV to-m, ward the firing hammer, adetent attached toy vthe diaphragm and normally adapteditogholdv the hammer in a :iixed position, a second snap i diaphragm secured at its periphery tothe' "core yadjacent tothe secondy side vof, the rst Ydia-K phragm, saidsecond diaphragmbeingfnornially' V-dished' in the'same direction as thefirst dia-f 

